Circuits and methods related to radio-frequency power couplers

ABSTRACT

Circuits and methods related to radio-frequency (RF) power couplers. In some embodiments, an RF circuit can include a first circuit having a frequency response that includes a feature within a selected frequency range, and a second circuit coupled to the first circuit such that the feature of the frequency response is at least in part due to the coupling. The RF circuit can further include an adjustment circuit configured to move the feature away from the selected frequency range. In some embodiments, such an RF circuit can be implemented in a packaged module which in turn can be included in a wireless device.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. application Ser. No.14/062,873 filed Oct. 24, 2013, entitled CIRCUITS AND METHODS FORREDUCING INSERTION LOSS EFFECTS ASSOCIATED WITH RADIO-FREQUENCY POWERCOUPLERS, which claims priority to and the benefit of the filing date ofU.S. Provisional Application No. 61/719,865 filed Oct. 29, 2012 entitledCIRCUITS AND METHODS FOR REDUCING INSERTION LOSS NOTCHES ASSOCIATED WITHRADIO-FREQUENCY POWER COUPLERS, the benefits of the filing dates ofwhich are hereby claimed and the disclosures of which are herebyexpressly incorporated by reference in their entirety.

BACKGROUND

1. Field

The present disclosure generally relates to reducing insertion losseffects associated with radio-frequency power couplers.

2. Description of the Related Art

In some wireless devices, power couplers can be used to, for example,limit maximum power of transmitted signals for a plurality of bands.Such power couplers can be daisy-chained together to share a coupledline, to thereby space on a circuit board.

Such a configuration can result in insertion loss notches associatedwith the daisy-chain line at high frequency bands due to variousinteractions. Problems associated with such insertion loss notches canbe more severe if an insertion loss notch in a frequency range of agiven band is sufficiently large and cannot be calibrated-out.

SUMMARY

In accordance with a number of implementations, the present disclosurerelates to a radio-frequency (RF) circuit that includes a first pathconfigured to route a first RF signal in a first band, and a second pathconfigured to route a second RF signal in a second band. The RF circuitfurther includes a power detector having a first coupler configured todetect power along the first path, and a second coupler configured todetect power along the second path. The first coupler and the secondcoupler are connected in a daisy-chain configuration. The RF circuitfurther includes an adjustment circuit implemented along at least one ofthe first path and the second path. The adjustment circuit is configuredto move a frequency response feature associated with the power detectorto a different frequency range.

In some embodiments, the adjustment circuit can be part of the secondpath. Each of the first path and the second path can include a poweramplifier (PA), an output match network connected to the PA, and therespective power coupler. The second path can further include theadjustment circuit implemented between the output match network and thesecond power coupler. The adjustment circuit can include an inductance,such as an inductor, implemented between the output match network andthe second power coupler. The adjustment circuit can further include acapacitance, such as a capacitor, connected in series with theinductance.

In some embodiments, the output match network can include a matchinginductance connected to an output of the PA, and a shunt capacitanceconnected to an output of the matching inductance.

In some embodiments, the frequency response feature can include a notchin a power spectrum associated with the power detector. In someembodiments, the first band can include an E-UTRA band B7, B38 or B40.The second band can include an E-UTRA band B18 or B8.

In some embodiments, the different frequency range can include a rangethat is not utilized by the first or second path. In some embodiments,the different frequency range can include a frequency range betweenE-UTRA bands B8 and B4. In some embodiments, the adjustment circuit canbe configured to move the notch to a lower frequency. In someembodiments, the lower frequency where the notch moves to can be betweenfrequencies associated with the first band and the second band.

In some implementations, the present disclosure relates to aradio-frequency (RF) module that includes a packaging substrateconfigured to receive a plurality of components, and an RF circuitimplemented on the packaging substrate. The RF circuit includes a firstpath configured to route a first RF signal in a first band, and a secondpath configured to route a second RF signal in a second band. The RFcircuit further includes a power detector having a first couplerconfigured to detect power along the first path and a second couplerconfigured to detect power along the second path. The first coupler andthe second coupler are connected in a daisy-chain configuration. The RFcircuit further includes an adjustment circuit implemented along atleast one of the first path and the second path. The adjustment circuitis configured to move a frequency response feature associated with thepower detector to a different frequency range.

In some embodiments, the RF module can be a power amplifier module, suchthat the first path includes an output of a first power amplifier (PA)and the second path includes an output of a second PA. In someembodiments, both of the first and second PAs can be implemented on asemiconductor die.

According to a number of implementations, the present disclosure relatesto a radio-frequency (RF) device that includes a transceiver configuredto process RF signals, and an antenna in communication with thetransceiver and configured to facilitate transmission of an amplified RFsignal. The RF device further includes a power amplifier (PA) moduleconnected to the transceiver and configured to generate the amplified RFsignal. The PA module includes a first path configured to route a firstRF signal in a first band, and a second path configured to route asecond RF signal in a second band. The PA module further includes apower detector having a first coupler configured to detect power alongthe first path and a second coupler configured to detect power along thesecond path. The first coupler and the second coupler are connected in adaisy-chain configuration. The PA module further includes an adjustmentcircuit implemented along at least one of the first path and the secondpath. The adjustment circuit is configured to move a frequency responsefeature associated with the power detector to a different frequencyrange. In some embodiments, the RF device can include a wireless device.

In a number of teachings, the present disclosure relates to aradio-frequency (RF) circuit that includes a first circuit having afrequency response that includes a feature within a selected frequencyrange. The RF circuit further includes a second circuit coupled to thefirst circuit such that the feature of the frequency response is atleast in part due to the coupling. The RF circuit further includes anadjustment circuit configured to move the feature away from the selectedfrequency range.

In some embodiments, the feature, such as an insertion loss notch, canbe moved to a lower frequency.

According to a number of implementations, the present disclosure relatesto a method for operating a radio-frequency (RF) device. The methodincludes detecting power along a first path and along a second path in adaisy-chain configuration. The first path is configured to route a firstRF signal in a first band, and the second path is configured to route asecond RF signal in a second band. The method further includes adjustingat least one of the first path and the second paths to move a frequencyresponse feature associated with the power detection to a differentfrequency range.

In some implementations, the present disclosure relates to a method foroperating a radio-frequency (RF) device. The method includes coupling afirst circuit and a second circuit, with the first circuit having afrequency response that includes a feature within a selected frequencyrange. The feature of the frequency response results at least in partdue to the coupling. The method further includes adjusting the secondcircuit to move the feature away from the selected frequency range.

For purposes of summarizing the disclosure, certain aspects, advantagesand novel features of the inventions have been described herein. It isto be understood that not necessarily all such advantages may beachieved in accordance with any particular embodiment of the invention.Thus, the invention may be embodied or carried out in a manner thatachieves or optimizes one advantage or group of advantages as taughtherein without necessarily achieving other advantages as may be taughtor suggested herein.

BRIEF DESCRIPTION OF THE DRAWINGS

FIGS. 1A and 1B show that in some configurations, a radio-frequency (RF)circuit can result in an undesirable response in a frequency band ofinterest.

FIGS. 2A and 2B show that in some implementations, an adjustment circuitcan be provided to the RF circuit of FIG. 1 to move the undesirableresponse away from the frequency band of interest.

FIG. 3 shows an example RF circuit that can result in an undesirableresponse in an operating band.

FIGS. 4A-4C show various examples of notches in frequency responsesassociated with the example circuit of FIG. 3.

FIGS. 5A and 5B show examples of RF circuits each having an adjustmentcircuit configured to move notch responses away from an operating band.

FIG. 6 shows an example of the adjustment circuit of FIG. 5.

FIG. 7 shows another example of the adjustment circuit of FIG. 5.

FIG. 8 shows examples of the notch responses moved away from theoperating band due to the adjustment circuit.

FIGS. 9 and 10 show that insertion loss performance can be generallymaintained with the inclusion of the adjustment circuit for an exampleoperating band.

FIGS. 11 and 12 show another example where insertion loss performancecan be generally maintained with the inclusion of the adjustment circuitfor another operating band.

FIG. 13 shows a process that can be implemented to operate an RF devicehaving one or more features as described herein.

FIG. 14 shows another process that can be implemented to operate an RFdevice having one or more features as described herein.

FIG. 15 shows that in some embodiments, one or more features of thepresent disclosure can be implemented in an RF module.

FIGS. 16A and 16B shows that in some embodiments, one or more featuresof the present disclosure can be implemented in wireless devices.

DETAILED DESCRIPTION OF SOME EMBODIMENTS

The headings provided herein, if any, are for convenience only and donot necessarily affect the scope or meaning of the claimed invention.

FIG. 1A schematically depicts a radio-frequency (RF) circuit 10 that canbe configured to receive an RF signal (RF_in) and generate an outputsignal (RF_out). In some situations, and as shown in FIG. 1B, such acircuit can yield a frequency response that includes an undesirabledecrease or increase within a selected frequency range 20. For example,a frequency response curve 12 is shown to include a peak 14 that residespartly within the frequency range 20 and exceeding a threshold value 16.In another example, a frequency response curve 32 is shown to include adip 34 that resides partly within the frequency range 20 and being belowa threshold value 36.

FIG. 2A shows that in some implementations, an RF circuit 100 caninclude an adjustment circuit 102. For the purpose of descriptionherein, it will be assumed that the RF circuit 100 without theadjustment circuit 102 can behave similar to the RF circuit described inreference to FIGS. 1A and 1B.

The presence of the adjustment circuit 102 is shown to yield adjustedfrequency responses, and examples of such adjustments are depicted inFIG. 2B. For example, a frequency response curve 112 that corresponds tothe example response curve 12 of FIG. 1B is shown to include a peak 114that has been moved out of the frequency range 20. Thus, the portion ofthe response curve 112 within the frequency range 20 is below thethreshold value 16. In another example, a frequency response curve 132that corresponds to the example response curve 32 of FIG. 1B is shown toinclude a dip 134 that has been moved out of the frequency range 20.Thus, the portion of the response curve 132 within the frequency range20 is above the threshold value 36.

In FIG. 2B, the example peak 114 and the example dip 134 are depicted asbeing moved (e.g., arrows 118, 138) to lower frequencies. It will beunderstood, however, that such movements can also be made to higherfrequencies.

FIG. 3 shows an example RF circuit 10 that can benefit from one or morefeatures as described herein. The circuit 10 generally relates to powercouplers for RF devices such as wireless handsets. Such power couplerscan be utilized to, for example, limit the maximum transmitted power orthe specific absorption rate (SAR) of wireless devices.

In the example circuit 10, a power coupler assembly can be generallyindicated as 70 and be configured to provide power detectionfunctionality for two example bands A and B. The first band A (e.g., ahigh band) is shown to be facilitated by Path A that includes an RFinput (RFIN_A) for a power amplifier (PA) 50 a. The PA 50 a can includeone or more stages, and an output of the last stage is shown to beconnected to an output matching network 60 a. Although not shown in FIG.3, Path A can also include an input matching network and/or one or moreinter-stage matching networks. An output of the matching network 60 a isshown to be coupled with a power coupling element before being providedto a duplexer 80 a configured to provide duplex functionality betweentransmission (e.g., of amplified RF signal through Path A) and reception(e.g., of received signal to RX_P_A and RX_N_A) utilizing one or moreantennas connected to a node ANT_A.

Similarly, the second band B (e.g., a low band) is shown to befacilitated by Path B that includes an RF input (RFIN_B) for a poweramplifier (PA) 50 b. The PA 50 b can include one or more stages, and anoutput of the last stage is shown to be connected to an output matchingnetwork 60 b. Although not shown in FIG. 3, Path B can also include aninput matching network and/or one or more inter-stage matching networks.An output of the matching network 60 b is shown to be coupled with apower coupling element before being provided to a duplexer 80 bconfigured to provide duplex functionality between transmission (e.g.,of amplified RF signal through Path B) and reception (e.g., of receivedsignal to RX_P_B and RX_N_B) utilizing one or more antennas connected toa node ANT_B.

In the example circuit 10, the PAs 50 a, 50 b are shown to be biased andcontrolled by a bias/control circuit 52. In some implementations, suchbiasing and/or controlling operations can be performed in known manners.

In the example circuit 10, the coupler output of each band can be eithercombined using a power-combiner circuit (not shown) or daisy-chainedtogether where every coupler shares a coupled line. The daisy-chaindesign can be used to, for example, save space on a circuit board (e.g.,a phone board) over the power-combining design.

In some configurations, power detection at an output of a low-band PAwith daisy-chain couplers can create insertion loss notches in thedaisy-chain line at high frequency bands due to output matching network,coupler, and/or duplexer interactions. In some situations, this problemcan be more severe for designs where higher-frequency bands exist alongwith low-frequency bands. The notch depth can vary; and can be equal toor greater than a transceiver detector's dynamic range and thereforetypically cannot be calibrated-out during phone board calibration. Inthe context of an example dual-band configuration, two of the foregoingdaisy-chain notches can be created.

FIGS. 4A-4C show examples of the notches in frequency response that canresult in daisy-chained couplers (e.g., 70 in FIG. 3) in the presence ofeither or both of the two RF paths (Path A and Path B). In FIG. 4A,simulated and measured responses of a daisy-chained coupler assembly areshown for forward power spectra in terms of S-parameter S21. Such adaisy-chained coupler assembly can be utilized for an example dual-bandPA circuit. In both responses, deep and significant notches are presentin a frequency range of about 2.0 to 2.6 GHz. Such a range can includeor overlap with E-UTRA (Evolved Universal Terrestrial Radio Access)operating frequency bands such as B7, B34, B38, and B40.

In FIG. 4B, similar simulated and measured responses of a daisy-chainedcoupler assembly are shown for forward power spectra in terms ofS-parameter S21. Such a daisy-chained coupler assembly is for anotherexample dual-band PA circuit. In both responses, deep and significantnotches are present in a frequency range of about 2.0 to 2.6 GHz. Such arange can include or overlap with E-UTRA operating frequency bands suchas B7, B34, B38, and B40.

In FIG. 4C, an example notch in forward power spectrum for S21 and anexample corresponding return loss (RL) peak are shown to providesignificant degradation at and around a frequency of about 2.0 GHz. Sucha frequency range can overlap significantly with, and thereby impact, anoperating band such as B1.

Lossless approaches to completely eliminate the foregoing daisy-chainnotches generally have not been successful. Described herein are variousexamples of circuits and methods for moving such a notch from anoperating band to a frequency range where the impact of the notch isreduced or substantially eliminated for that operating band. In someimplementations, such a frequency range where the notch is moved to caninclude an unused frequency range. In some implementations, the unusedfrequency range can be completely unused for a given wireless device. Insome implementations, the unused frequency range can include a rangethat is unused during operation in the operating band, but can be usedin another operating mode.

FIGS. 5A and 5B show examples of circuits that are similar to theexample circuit 10 of FIG. 3, but with an adjustment circuit 102provided in a given RF signal path. Examples of such an adjustmentcircuit 102 are described herein in greater detail. FIG. 5A shows thatone or more features of the present disclosure can be implemented in aconfiguration having two RF signal paths similar to the example of FIG.3. FIG. 5B shows that one or more features of the present disclosure canbe implemented in a configuration having more than two RF signal paths.

The example configuration shown in FIG. 5A is similar to that of FIG. 3,but with an addition of adjustment circuits 102 a, 102 b having one ormore features as described herein. Examples of circuit segments 150 a,150 b with each including its respective last stage of the PA 50 (50 afor the circuit segment 150 a, and 50 b for the circuit segment 150 b),output matching network 60 (60 a for the circuit segment 150 a, and 60 bfor the circuit segment 150 b), and adjustment circuit 102 (102 a forthe circuit segment 150 a, and 102 b for the circuit segment 150 b), aredescribed herein in greater detail.

The example configuration shown in FIG. 5B is similar to that of FIG.5A, but with an addition of a third RF signal path (Path C) and acorresponding adjustment circuit 102 c. Examples of circuit segments 150a, 150 b, 150 c with each including its respective last stage of the PA50, output matching network 60, and adjustment circuit 102, aredescribed herein in greater detail.

In the examples of FIGS. 5A and 5B, each RF path is shown to include anadjustment circuit 102. In some implementations, not all RF paths needto have such adjustment circuits. For example, high band couplers donot, in general, cause problems in frequencies or frequency ranges ofinterest (e.g., 0.5 to 2.6 GHz). Notch-responses resulting from suchhigh band couplings are typically located at much higher frequencies(e.g., around 5.5 GHz). Accordingly, in such an example configuration, ahigh band RF path may or may not have an adjustment circuit 102.

FIG. 6 shows an example of the circuit segment 150 described inreference to FIGS. 5A and 5B. In some embodiments, the circuit segment150 of FIG. 6 can be implemented for each of the circuit segments 150 aand 150 b of FIG. 5A, and circuit segments 150 a-150 c of FIG. 5B. Inthe example, an RF signal being amplified is shown to be provided to abase of a bipolar-junction transistor (BJT) associated with the laststage of a PA (50 in FIGS. 5A and 5B). A collector of the BJT is shownto provide an output of the last stage of the PA, and such an outputsignal is shown to be matched by an output match network 60. It will beunderstood that other types of transistors can also be utilized in thePA 50.

The example output match network 60 is shown to include an inductance L1(e.g., an inductor) along a path connected to the collector of the BJT.The output match network 60 is shown to further include a shuntcapacitance C1 (e.g., a capacitor) between the output of the inductanceL1 and ground. In some embodiments, a capacitance can be provided so asto be in series with the inductance L1. It will be understood that othertypes of output match networks can also be utilized.

FIG. 6 shows that in some implementations, an adjustment circuit 102 caninclude an inductance L2 (e.g., an inductor) that is connected in serieswith the inductance L1. Thus, the amplified signal can travel from thecollector of the BJT, through L1, and through L2 before being providedto a coupling section (e.g., respective portion of daisy-chainedcouplers 70 in FIGS. 5A and 5B).

FIG. 7 shows another example of the circuit segment 150 described inreference to FIGS. 5A and 5B. In the example, the last stage of the PA50 and the output matching network 60 can be similar to those describedin reference FIG. 6.

FIG. 7 shows that in some implementations, an adjustment circuit 102 caninclude an inductance L2 (e.g., an inductor) and a capacitor C2 (e.g., acapacitor) connected in series with the inductance L1. Thus, theamplified signal can travel from the collector of the BJT, through L1,through L2, and through C2 before being provided to a coupling section(e.g., respective portion of daisy-chained couplers 70 in FIGS. 5A and5B).

In some implementations, some or all of the foregoing examples of theadjustment circuit 102 can be configured to modify the out-of-bandimpedance of the output matching network to shift the notch frequencyassociated with the daisy-chained coupler assembly into, for example, anunused frequency range between Band 8 and Band 4 (e.g., 0.960 to 1.710GHz). In some embodiments, the series-LC circuit 102 of FIG. 7 can beconfigured to provide the foregoing functionality while better reducingor minimizing degradations of other performance factors, such asinsertion loss and flatness over frequency, than the inductance-onlycircuit 102 of FIG. 6.

In some implementations, each of the adjustment circuits 102 of FIGS. 6and 7 can replace a capacitance (not shown) that is provided along theRF signal path after the output matching network 60 but before the powercoupling section. Examples of such replacements and beneficial effectsare described herein in greater detail.

FIG. 8 shows examples of how a notch that covers or overlaps with one ormore operating bands can be moved to an unused frequency range such asthe foregoing example range between Band 8 and Band 4. A curve 160corresponding to the circuit of FIG. 3 is shown to include a notch 162having values less than an example threshold value of −2 dB in afrequency range that undesirably covers or overlaps with bands B7, B38,and B40.

In the example of FIG. 8, curves 170 and 180 are shown to have theirrespective notches 172, 182 moved into the unused frequency rangebetween the B8 and B4 bands. The portions of the curves 170, 180 thatcover or overlap with the foregoing B7/B38/B40 bands are shown to havevalues that are well above the −2 dB threshold.

An arrow 164 indicates an approximate gain that can be achieved betweenthe notch 162 of the curve 160 and the generally flattened response ofthe example curve 180. An arrow 166 representative of a power detectiondynamic range (e.g., 4 dB) shows that the unadjusted notch 162 isundesirably close to exceeding the dynamic range, while the shiftednotches 172, 182 are well within the dynamic range. Thus, if calibrationis desired for either or both of the responses 170, 180, it can beachieved.

The example response curve 170 having its notch 172 shifted out of theoperating bands B7/B38/B40 corresponds to an adjustment circuit 102 ofFIG. 7 provided for an example low-band B18 signal path. The shuntcapacitance C1 of the output matching network 60 has a value ofapproximately 7.6 pF. The inductance L2 and capacitance C2 of theadjustment circuit 102 have values of approximately 4.3 nH and 5.6 pF,respectively. The adjustment circuit 102 replaces an approximately 18 pFcapacitance (not shown) along the signal path at the output of theoutput matching network 60. In the example of FIG. 7, L1 is an outputmatch inductance (e.g., an inductor coil) which can be implemented as atrace rather than being a distinct surface-mount component. Theinductance of L1, having a value of about 2.3 nH in the example,generally does not change in response to the introduction of theadjustment circuit 102.

The example response curve 180 having its notch 182 shifted out of theoperating bands B7/B38/B40 corresponds to an adjustment circuit 102 ofFIG. 7 provided for an example low-band B8 signal path. The shuntcapacitance C1 of the output matching network 60 has a value ofapproximately 6.8 pF. The inductance L2 and capacitance C2 of theadjustment circuit 102 have values of approximately 4.7 nH and 5.1 pF,respectively. The adjustment circuit 102 replaces an approximately 18 pFcapacitance (not shown) along the signal path at the output of theoutput matching network 60.

FIGS. 9-12 show that the adjustment circuits as described herein canprovide the desirable notch-shifting functionality (e.g., FIG. 8)without significantly degrading performance in other areas. FIGS. 9 and10 show Smith charts for S11 parameter for the example low-band B18signal path with (e.g., curve 170 of FIG. 8) and without (e.g., curve160 of FIG. 8) an adjustment circuit, respectively. FIGS. 11 and 12 showSmith charts for S11 parameter for the example low-band B8 signal pathwith (e.g., curve 180 of FIG. 8) and without (e.g., curve 160 of FIG. 8)an adjustment circuit, respectively. For all of the foregoing exampleconfigurations, each signal path has a load impedance of approximately50 ohms.

For the B18 band example (FIGS. 9 and 10), input impedance (Zin)measurements were obtained at three frequencies, and the results arelisted in Table 1. One can see that the Zin values for the B18 signalpath with the adjustment circuit compare favorably with those for theB18 signal path without the adjustment circuit.

TABLE 1 B18 Zin without B18 Zin with adjustment circuit adjustmentcircuit Frequency (MHz) (FIG. 9) (Ohm) (FIG. 10) (Ohm) 816 3.282 -j2.094 3.192 - j2.005 832 3.317 - j0.468 3.226 - j0.448 848 3.184 -j1.832 3.173 - j1.815

For the B8 band example (FIGS. 11 and 12), input impedance (Zin)measurements were obtained at three frequencies, and the results arelisted in Table 2. One can see that the Zin values for the B8 signalpath with the adjustment circuit also compare favorably with those forthe B8 signal path without the adjustment circuit.

TABLE 2 B8 Zin without B8 Zin with adjustment circuit adjustment circuitFrequency (MHz) (FIG. 11) (Ohm) (FIG. 12) (Ohm) 882 3.894 - j1.4533.946 - j1.485 898 3.504 - j0.908 3.618 - j0.971 913 3.456 - j1.8193.521 - j1.954

FIG. 13 shows a process 200 that can be implemented to operate an RFdevice having one or more features as described herein. In someembodiments, such an RF device can include one or more circuits such asthe examples described in reference to FIGS. 5-7. In block 202, adaisy-chain power detection configuration can be provided for first andsecond RF signal paths. In block 204, at least one of the first andsecond RF paths can be adjusted to move a frequency response featureassociated with the power detection to a different frequency range.

FIG. 14 shows a process 210 that can be implemented to operate an RFdevice having one or more features as described herein. In someembodiments, such an RF device can include one or more circuits such asthe examples described in reference to FIGS. 5-7. In block 212, a firstcircuit and a second circuit of an RF device can be coupled, such thatthe first circuit includes a frequency response having a feature in aselected frequency range resulting from the coupling. In someembodiments, such a coupling can be implemented as a daisy-chained powerdetection circuit configured to detect output power levels of first andsecond RF power amplifiers. In block 214, the second circuit can beadjusted to move the feature away from the selected frequency range. Insome implementations, the feature can include a notch in the frequencyresponse. In some implementations, such a notch can be moved to a lowerfrequency range that is not utilized by either of the first and secondcircuits.

In some implementations, one or more features described herein can beincluded in a module. FIG. 15 schematically depicts an example module300 that includes a PA die 302 having a PA 50 for each of a plurality ofamplification paths. By way of examples, first and second amplificationpaths are shown to include PAs 50 a, 50 b each having one or morestages; and input RF signals (RFIN_A, RFIN_B) to the PAs 50 a, 50 b areshown to be provided through their respective input match networks 308a, 308 b.

The PAs 50 a, 50 b are shown to be in communication with a bias/controlcircuit 52 (lines 306 a, 306 b). The bias/control circuit 52 can beconfigured to provide bias and/or control functionality for the PAs 50a, 50 b in known manners, based on, for example, a control signal input304. In some embodiments, the bias/control circuit 52 can be implementedin a die that is separate from the PA die 302. In some embodiments, thebias/control circuit 52 can be implemented in the same die as the PA die302.

An output of the first PA 50 a is shown to be connected to a firstmatching network 60 a. Similarly, an output of the second PA 50 b isshown to be connected to a second matching network 60 b.

An output of the first matching network 60 a is shown to be connected toa first adjustment circuit 102 a having one or more features describedherein. Similarly, an output of the second matching network 60 b isshown to be connected to a second adjustment circuit 102 b having one ormore features described herein. In some embodiments, an inductanceassociated with each of the first and second adjustment circuits 102 a,102 b can be provided by a discrete component (e.g., surface-mountedinductor), one or more conductor paths, or some combination thereof. Inembodiments where a capacitance is in series with the foregoinginductance, such a capacitance can be provided by, for example, adiscrete component (e.g., surface-mounted capacitor).

An output of the first adjustment circuit 102 a is shown to be connectedto a power coupling section 70 a before being routed to an output node(RFOUT_A). Similarly, an output of the second adjustment circuit 102 bis shown to be connected to a power coupling section 70 b before beingrouted to an output node (RFOUT_B). In the example shown, the first andsecond power coupling sections 70 a, 70 b are shown to be daisy-chainedtogether between a coupler input 310 and an output 312.

As described herein, the foregoing daisy-chain between thepower-coupling sections can result in one signal path (e.g., a low-bandpath) impacting the other signal path (e.g., high-band path) by way of,for example, a notch response in one or more operating bands associatedwith the other signal path (e.g., high-band path). In some situations,the reverse effect (e.g., the high-band impacting the low-band throughthe daisy-chain coupling) may not be present, be present in relativelylow magnitude, or be present in a frequency range that is of little orno concern (e.g., in a frequency range that is not used by any bands).In the context of the example high band described herein,notch-responses associated with such a high band are typically locatedat much higher frequencies (e.g., between 5 to 6 GHz) that generally donot impact other operating bands. Accordingly, in such a situation, thefirst signal path (e.g., a high-band path) may or may not have anadjustment circuit (102 a). Thus, it will be understood that for aplurality of signal paths as described herein, some or all of such pathscan include adjustment circuit(s).

In the example module 300 of FIG. 15, various components describedherein can be provided or formed on or within a packaging substrate 320.In some embodiments, the packaging substrate 320 can include a laminatesubstrate. In some embodiments, the module 300 can also include one ormore packaging structures to, for example, provide protection andfacilitate easier handling of the module 300. Such a packaging structurecan include an overmold formed over the packaging substrate 320 anddimensioned to substantially encapsulate the various circuits andcomponents thereon.

In some implementations, a device and/or a circuit having one or morefeatures described herein can be included in an RF device such as awireless device. Such a device and/or a circuit can be implementeddirectly in the wireless device, in a modular form as described herein,or in some combination thereof. In some embodiments, such a wirelessdevice can include, for example, a cellular phone, a smart-phone, ahand-held wireless device with or without phone functionality, awireless tablet, etc.

FIGS. 16A and 16B schematically depict an example wireless device 400having one or more advantageous features described herein. The exampleshown in FIG. 16A is for a frequency-division duplexing (FDD)configuration, and the example shown in FIG. 16B is for a time-divisionduplexing (TDD) configuration.

In each of the two example wireless devices of FIGS. 16A and 16B, PAs50, their input and output matching circuits (60), adjustment circuits102, and coupling circuits 70 can be implemented on a module 300 asdescribed in FIG. 15. The PAs 50 can receive their respective RF signalsfrom a transceiver 410 that can be configured and operated in knownmanners. The transceiver 410 can be configured to generate the RFsignals to be amplified and transmitted, and to process receivedsignals. The transceiver 410 is shown to interact with a basebandsub-system 408 that is configured to provide conversion between dataand/or voice signals suitable for a user and RF signals suitable for thetransceiver 410. The transceiver 410 is also shown to be connected to apower management component 406 that is configured to manage power forthe operation of the wireless device. Such power management can alsocontrol operations of the baseband sub-system 408 and the module 300.

The baseband sub-system 408 is shown to be connected to a user interface402 to facilitate various input and output of voice and/or data providedto and received from the user. The baseband sub-system 408 can also beconnected to a memory 404 that is configured to store data and/orinstructions to facilitate the operation of the wireless device, and/orto provide storage of information for the user.

In the example wireless device 400 of FIG. 16A, outputs of the module300 are shown to be routed to an antenna 416 via their respectiveduplexers 80 a, 80 b and a band-selection switch 414. The band-selectionswitch 414 can include, for example, a single-pole-double-throw (e.g.,SPDT) switch to allow selection of an operating band. Although depictedin the context of the two-band output of the module 300, it will beunderstood that the number of operating bands can be different. Inconfigurations where multiple bands are involved, such a band-selectionswitch can have, for example, an SPMT (single-pole-multiple-throw)configuration.

In the example of FIG. 16A, each duplexer 80 can allow transmit andreceive operations to be performed substantially simultaneously using acommon antenna (e.g., 416). In FIG. 16A, received signals are shown tobe routed to “Rx” paths (not shown) that can include, for example, alow-noise amplifier (LNA).

In the example wireless device 400 of FIG. 16B, time-division duplexing(TDD) functionality can be facilitated by low-pass filters (LPF) 82 a,82 b connected to the two example outputs of the module 300. The pathsout of the filters 82 a, 82 b are shown to be connected to an antennathrough a switch 414. In such a TDD configuration, Rx path(s) can comeout of the switch 414. Thus, the switch 414 can act as band selector(e.g., between high-band and low-band as described herein), as well as aTx/Rx (TR) switch.

In the example wireless devices 400 depicted in FIGS. 16A and 16B, theexample module 300 is depicted as including the PAs (50 a, 50 b) andtheir respective matching circuits (60 a, 60 b), adjustment circuits(102 a, 102 b), and coupler sections (70 a, 70 b). In some embodiments,the module 300 of FIG. 16A can include some or all of the duplexers 80a, 80 b and the switch 414. In some embodiments, the module 300 of FIG.16B can include some or all of the filters 82 a, 82 b and the switch414.

A number of other wireless device configurations can utilize one or morefeatures described herein. For example, a wireless device does not needto be a multi-band device. In another example, a wireless device caninclude additional antennas such as diversity antenna, and additionalconnectivity features such as Wi-Fi, Bluetooth, and GPS.

Various examples are described herein in the context of E-UTRA (EvolvedUniversal Terrestrial Radio Access) operating bands. Such bands caninclude frequency bands listed in Table 3.

TABLE 3 Operating band Frequency band (MHz) 1 2,100 2 1,900 3 1,800 41,700 5 850 6 800 7 2,600 8 900 9 1,700 10 1,700 11 1,500 12 700 13 70014 700 17 700 18 800 19 800 20 800 21 1,500 22 3,500 23 2,000 24 1,60025 1,900 26 850 27 800 28 700 29 800 30 2,300 33 2,100 34 2,100 35 1,90036 1,900 37 1,900 38 2,600 39 1,900 40 2,300 41 2,500 42 3,500 43 3,70044 700It will be understood that each of the example frequency bands listed inTable 3 can include one or more frequency ranges. For example, a FDDband can be associated with a transmit frequency range and a receivefrequency range. For a TDD band, a given frequency range can facilitateboth transmit and receive operations. It will also be understood thatone or more features of the present disclosure can be implemented inother band-designation conventions.

Unless the context clearly requires otherwise, throughout thedescription and the claims, the words “comprise,” “comprising,” and thelike are to be construed in an inclusive sense, as opposed to anexclusive or exhaustive sense; that is to say, in the sense of“including, but not limited to.” The word “coupled”, as generally usedherein, refers to two or more elements that may be either directlyconnected, or connected by way of one or more intermediate elements.Additionally, the words “herein,” “above,” “below,” and words of similarimport, when used in this application, shall refer to this applicationas a whole and not to any particular portions of this application. Wherethe context permits, words in the above Description using the singularor plural number may also include the plural or singular numberrespectively. The word “or” in reference to a list of two or more items,that word covers all of the following interpretations of the word: anyof the items in the list, all of the items in the list, and anycombination of the items in the list.

The above detailed description of embodiments of the invention is notintended to be exhaustive or to limit the invention to the precise formdisclosed above. While specific embodiments of, and examples for, theinvention are described above for illustrative purposes, variousequivalent modifications are possible within the scope of the invention,as those skilled in the relevant art will recognize. For example, whileprocesses or blocks are presented in a given order, alternativeembodiments may perform routines having steps, or employ systems havingblocks, in a different order, and some processes or blocks may bedeleted, moved, added, subdivided, combined, and/or modified. Each ofthese processes or blocks may be implemented in a variety of differentways. Also, while processes or blocks are at times shown as beingperformed in series, these processes or blocks may instead be performedin parallel, or may be performed at different times.

The teachings of the invention provided herein can be applied to othersystems, not necessarily the system described above. The elements andacts of the various embodiments described above can be combined toprovide further embodiments.

While some embodiments of the inventions have been described, theseembodiments have been presented by way of example only, and are notintended to limit the scope of the disclosure. Indeed, the novel methodsand systems described herein may be embodied in a variety of otherforms; furthermore, various omissions, substitutions and changes in theform of the methods and systems described herein may be made withoutdeparting from the spirit of the disclosure. The accompanying claims andtheir equivalents are intended to cover such forms or modifications aswould fall within the scope and spirit of the disclosure.

What is claimed is:
 1. A radio-frequency (RF) circuit comprising: afirst circuit having a frequency response that includes a feature withina selected frequency range; a second circuit coupled to the firstcircuit such that the feature of the frequency response is at least inpart due to the coupling; and an adjustment circuit configured to movethe feature away from the selected frequency range.
 2. The RF circuit ofclaim 1 wherein the feature is moved to a lower frequency.
 3. The RFcircuit of claim 1 wherein the adjustment circuit is part of the secondcircuit.
 4. The RF circuit of claim 3 wherein each of the first circuitand the second circuit includes a power amplifier (PA), an output matchnetwork connected to the PA, and a power coupler, the second circuitfurther including the adjustment circuit implemented between the outputmatch network and the power coupler.
 5. The RF circuit of claim 4wherein the adjustment circuit includes an inductance implementedbetween the second output match network and the second power coupler. 6.The RF circuit of claim 5 wherein the inductance includes an inductor.7. The RF circuit of claim 5 wherein the adjustment circuit furtherincludes a capacitance connected in series with the inductance.
 8. TheRF circuit of claim 7 wherein the capacitance includes a capacitor. 9.The RF circuit of claim 4 wherein the output match network of each ofthe first circuit and the second circuit includes a matching inductanceconnected to an output of the PA, and a shunt capacitance connected toan output of the matching inductance.
 10. The RF circuit of claim 1wherein the frequency response feature includes a notch in a powerspectrum associated with the coupling.
 11. The RF circuit of claim 1wherein the selected frequency range includes or at least partiallyoverlaps with an E-UTRA band B7, B38 or B40.
 12. The RF circuit of claim11 wherein the feature is moved to a frequency range that does notoverlap with the selected frequency range.
 13. The RF circuit of claim12 wherein the frequency range to which the feature is moved includes afrequency range between E-UTRA bands B8 and B4.
 14. A method foroperating a radio-frequency (RF) device, the method comprising: couplinga first circuit and a second circuit, the first circuit having afrequency response that includes a feature within a selected frequencyrange, the feature of the frequency response resulting at least in partdue to the coupling; and moving the feature away from the selectedfrequency range.
 15. The method of claim 14 wherein the feature is movedto a lower frequency.
 16. The method of claim 15 wherein each of thefirst circuit and the second circuit includes a power amplifier (PA), anoutput match network connected to the PA, and a power coupler, thesecond circuit further including an adjustment circuit implementedbetween the output match network and the power coupler, the moving ofthe feature facilitated at least in part by the adjustment circuit. 17.The method of claim 16 wherein the adjustment circuit includes aninductance implemented between the second output match network and thesecond power coupler.
 18. The method of claim 17 wherein the adjustmentcircuit further includes a capacitance connected in series with theinductance.
 19. The method of claim 14 wherein the frequency responsefeature includes a notch in a power spectrum associated with thecoupling.
 20. A wireless device comprising: a transceiver configured toprocess radio-frequency (RF) signals; an antenna in communication withthe transceiver, the antenna configured to facilitate transmission of anamplified RF signal; and a power amplifier (PA) module connected to thetransceiver, the PA module configured to generate the amplified RFsignal, the PA module including an RF circuit implemented on a packagingsubstrate, the RF circuit including a first circuit having a frequencyresponse that includes a feature within a selected frequency range, anda second circuit coupled to the first circuit such that the feature ofthe frequency response is at least in part due to the coupling, the RFcircuit further including an adjustment circuit configured to move thefeature away from the selected frequency range.